How bike-sharing conquered the world

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“Health benefits are harder to quantify, especially in smoggy cities like Beijing. Mobike has found that its bikes are used more or less as much when the air is really bad as when it is not, suggesting that the good done by exercise may be undone by heavy breathing in toxic air. But in less-polluted cities the gains from exercise are larger than the risks from road accidents or air pollution, according to a study of Barcelona in the British Medical Journal.
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